Many of the wonderful conveniences of modern life are made easily available to ordinary people through the economic efficiency of mass production and other high volume processing techniques, of which virtually all require materials to be brought to and from particular locations in bulk quantities. Consequently, many varieties of bulk material containers used commercially have become well known. They are used for the accumulation, storage and transport of solid and liquid matter, and at all stages of the life of the contained matter, whether raw material, processed product, or waste remaining after usage or consumption of the product. Such large capacity containers are typically substantially rectangular in shape, for easy accommodation by trucks and railway cars.
A contemporary variant of such a container is exemplified in U.S. Pat. No. 5,281,073, incorporated herein by reference as if more fully set forth. The designs shown therein have the desirable feature of being nestable configurations, which in turn allows for more efficient utilization of space, whether during storage or transport, when the containers are empty. Another feature of the multiple aperture construction taught therein is that the containers may be carried or manipulated using machinery having common forklift type blades. This feature may not necessarily be beneficial, since when exploiting the nestability of the container design, the apertures further from the ground must be accessed, and in practice a common size for the container is on the order of twenty feet long, eight feet wide, and four feet high. This would require that a lifting fork, to be fully useful in stack operations with such containers, while only requiring four to six feet of vertical lifting travel to clear a stack of containers, be raised to an overall height of perhaps eight or ten feet, since lifting in stack operations begins at a point approximately four feet high. This may well exceed the range of smaller forklifts otherwise capable of lifting such containers. In practice it thus becomes necessary to use a larger forklift to handle the containers for stack operations, which seems wastefully inefficient when considering the containers are usually empty at this stage, and therefore lightest in weight.
Another consideration exists as pertains to the structures of the container which have apertures for lifting by insertion of forklift blades therethrough, such as the container side walls or support rails. The relatively small area of the structure defining the apertures must withstand supporting the container when loaded to capacity, being handled roughly, and perhaps being driven quickly across rough surfaces.
These apertured components must be fabricated of thicker and stronger material than would otherwise be required because not only must the container and the load therein be supported, but to resist damage localized to the aperture areas caused by the inserted blades during rough or abusive handling operations. The disadvantage of apertures and blade through handling therefore exact their price in container fabrication cost, as well as lost payload capacity, reduced life span, and the full host of other penalties associated with the additional container weight. In the case of container designs having upper longitudinal support rails, the weight problem caused by increasing the structure size to compensate for the weakness caused by the apertures and the blade therethrough handling, is exacerbated by the fact that these oversized and overweight rails are often extended across the ends of the container to form an external continuous, perimetric reinforcing rim.
Another disadvantage of the aforementioned container design is that it necessitates an approach from the side of the container by a manipulating vehicle. Under many circumstances it may be desirable to transport the container in enclosed fashion, such as in the box type body of a truck, railway car, or shipping container. This may be because it is desirable to prevent external foreign matter from contaminating the material carried in the container, or to prevent loss of the contained material, or to prevent exposure to the elements. It may also be desirable for financial considerations because such enclosed shipping bodies are very plentiful and inexpensively available for transporting the containers or material in them.
While the size and shape of these containers often enables their carriage within these box type shipping bodies, these enclosed bodies typically open at the ends for loading and unloading. This requires that the containers be carried and lifted for loading and unloading into box bodies by machinery from a position longitudinally oriented to the end of the container. The task is not ordinarily possible by a single manipulating machine which as described above, is positioned transversely oriented to the side of the container. In order to load such a container into a common box body with a single forklift, some form of staging platform must be used where the container can be placed in alignment with the opening in the box body, and then a ramp to the staging platform provided so the forklift can push the container in a longituinal direction into the box. Even with the additional cost and space requirements of the ramp and staging platform, the dragging and sliding of the container would likely prove destructive to both the container and the floor of the box body. To address this problem by adding wheel elements to the containers would again add weight, complexity and cost to the operation.
Consequently, a need exists for a tool or apparatus which enables an ordinary forklift type machine to engage the upper peripheral rim or lip of a bulk material container, so that the container can be lifted, carred or manipulated thereby.